Various attempts have been made to overcome the problem of dye bleeding and/or dye transfer in laundry processes. The term “dye bleeding” often refers to the fact that certain dyes will come off the fabrics during laundering, thereby causing color fading of the fabrics. Such a phenomenon seems to be more prominent for cellulosic fabrics dyed with non-reactive dyes such as direct, vat, azoic and sulfur dyes (D R. Warring and G. Hallas, “The chemistry and application of dyes”, Plenum Press, New York, 1990). Dyes that come off the fabrics are often called “migrating dyes” and the process to overcome dye bleeding are often referred to as “dye fixation”.
On the other hand, there is also a need to take care of the migrating dyes that have already come off the fabrics and are present in the wash liquor. Otherwise, such migrating dyes might redeposit on fabric surfaces and thereby cause color contamination. This process is often referred to as “dye transfer inhibition” and/or “stain inhibition”.
Hence there is a need for additives that can be added into laundry detergents and/or after rinse products to help either prevent dyes on fabrics from bleeding, i.e. fixing, or substances that can prevent migrating dyes from re-deposition. Indeed much efforts have been made to overcome such problems, and substances that could help tackle such problems are often referred as dye fixatives, dye transfer inhibitors, anti-deposition agents, dye scavengers and/or staining inhibitors.
For example, U.S. Pat. No. 3,694,364, there is disclosed the use of tertiary polymeric amines which function as anionic dye scavengers. The polymeric amines are chemically affixed on the surface of a substrate material such as cellulosic materials, for example, cotton in any of its forms, purified cotton cellulose, cellulose sponge and the like. To affix the polymeric amines, the cotton substrate is modified by phosphorylation and chemisorption of the polymeric amine. In related U.S. Pat. No. 3,673,110, there is disclosed the use of both the tertiary polymeric amines and quaternary ammonium compounds as the dye scavenging material. The latter Edwards patent discloses other processes for chemically affixing the dye scavenger compounds to a cellulosic material substrate also for use in controlling undesirable random dyes in a liquid bath such as when laundering textile articles. For example, the hydroxylated surface of the cellulosic material is chemically modified to establish anionic functional groups. Each of the anionic functional groups is capable of chemically binding nitrogen compounds such as the aforementioned disclosed dye scavenger compounds.
In addition to modifying the fabric surface to present dye transfer, it is also possible to add into the laundry sacrificial materials that absorb migrating dyes, thereby prevent the re-deposition on fabrics of value and concern. Such materials are often made in the form of fabrics treated with various chemicals that are believed to be capable to attracting dyes from the wash liquor. In Kleinschmidt, U.S. Pat. No.3,816,321 there is disclosed a dye scavenging article for scavenging anionic dyes released from dyed fabrics being laundered to prevent dye transfer during the laundry process. The dye-scavenging article includes a support matrix such as a polyurethane material to which there is chemically bonded a dye-scavenging compound. The dye-scavenging compound includes polyquartenary ammonium compounds.
U.S. Pat. No. 4,380,453 discloses generally the use of N-trisubstituted ammonium-2-hydroxy-3-halopropyl compounds and salts of epoxy propyl ammonium as dye scavenger compounds. The preferred dye scavenger compound is glycidyltrimethylammonium chloride, which is applied to, adsorbed by, or impregnated in the cellulosic material substrate. The resulting cellulosic material substrate is disclosed as being suitable for use in conventional washing machines for laundering clothes to eliminate random dyes from the wash and rinse waters, thereby eliminating undesirable discoloration of clothes due to the transfer of dyes from other clothes in the washing machine.
U.S. Pat. No. 5,698,476 discloses an article for removing extraneous, random free-flowing dyes from laundry washing applications. The laundry article includes two components, a dye absorber and a dye transfer inhibitor, which are introduced into the wash water via a support matrix. The dye absorber is chemically attached to the support matrix to maintain a relational association during the laundry washing application. On the other hand, the dye transfer inhibitor is released from the support matrix into the wash water to be evenly distributed during the laundry washing application.
U.S. Pat. No. 5,698,476 discloses materials that are suitable as dye absorbers for the laundry article, including quaternary N-substituted ammonium)-hydroxy-haloalkyl compounds such as 2-hydroxy-3-chloropropoyltrimethylammonium chloride; polyquaternary ammonium compounds; polyamphoterics; quaternized starches; proteins; chitin or its hydrolyzed form, chitosan; choline chloride; polyvinyl amine (PVAm); polyethylene imine (PEI); as well as combinations thereof. Dye transfer inhibitors include polyvinyl pyrrolidone, polyvinyl alcohol, polyvinyl Imidazole, polyamine-N-oxides, cationic starches, magnesium aluminate, hydrotalcite, proteins, hydrolyzed proteins, polyethylene imines, polyvinyl oxazolidone, enzymes, oxidants, cationic surfactants, amphoteric surfactants, propylene oxide reaction products, polyamino acids, block co-polymers of alkylene oxides, polyamines, polyamides, methyl cellulose, carboxyalkyl, celluloses, guar gum, natural gums, alginic acid, polycarboxylic acids, cydodextrins and mixtures.
Another approach for tackling the problem of undesirable dye transfer is through the use of an oxidation catalyst that is capable of removing migrating dyes in the wash liquor, thereby preventing re-deposition. Such catalysts, e.g. selected manganese complexes, can be added into laundry detergents as special additives.
Certain polymers have also been found to be useful in preventing migrating dyes from re-deposition. For examples, the use of poly(vinyl pyridine) and its various derivatives and co-polymers in preventing dye re-depositions can be found in the following references.
U.S. Pat. No. 6,348,441 discloses a method for laundering soiled fabrics using a non-aqueous detergent formulated to control dye transfer and sudsing in high efficiency washing machine. U.S. Pat. No. 5,466,802 discloses the use of quaternary polyvinylpyrridinium derivatives as anti-dye transfer agent. U.S. Pat. No. 6,306,815 discloses the use of quaternary polyvinylpyrridinium derivatives as anti-dye transfer agents. U.S. Pat. No. 5,380,447 discloses a process and fabric finishing compositions for preventing the deposition of dye in fabric finishing processes. U.S. Pat. No. 6,191,098 discloses polyvinylpyridinium derivatives as anti-dye transfer agents. U.S. Pat. No. 6,156,829 discloses a product and process for making quaternized, water-soluble vinylpyridine carboxylate polymers. U.S. Pat. No. 6,271,386 discloses a product and process for making quaternized, water-soluble vinylpyridine carboxylate polymers. U.S. Pat. No. 6,103,831 discloses water-soluble dye complexing polymers. U.S. Pat. No. 5,863,879 discloses dye transfer inhibitors for detergents (BASF, vinylamine derivatives). U.S. Pat. No. 6,165,969 discloses the use of quaternized polymerizates containing units of vinyl imidazole as a color fixing and color transfer inhibiting additive to detergent post-treatment agents and detergents. U.S. Pat. No. 5,830,844 discloses dye transfer inhibitors for detergents: Water-insoluble particles, crosslinked polymers containing polymerized units of 1-vinylpyrrolidone and/or 1-vinylimidazoles).
Various derivatives based on vinylpyridinum, poly(vinylpyridine-N-oxide) have been found to be efficient dye transfer inhibitors. The preparation and application of such compounds have been documented in U.S. Pat. No. 6,121,223 and U.S. Pat. No. 5,149,456.
Amine based products are believed to be able to provide dye transfer inhibition properties. For example, the use of N,N,N′,N′-tetrakis-(2-hydroxypropyl) ethylenediamine) as dye transfer inhibitors is explored in U.S. Pat. No. 5,827,813. Other references relating to the use of amine based substances as dye transfer inhibitors include U.S. Pat. No. 6,251,846, U.S. Pat. No. 6,156,722 and U.S. Pat. No. 6,140,292.
In addition to the aforementioned references, the use of polyglycosides (U.S. Pat. No. 6,159,921) and various enzymes exhibiting peroxidase activities (U.S. Pat. No. 5,855,621) as dye transfer inhibitors is referred.
In comparison to the seemingly plentiful references on various substances and their utilities as laundry detergents to provide dye transfer inhibition properties, there appears to be very few references on substances that could help prevent bleeding of dyes from fabrics. Among the very few citations, the use of bis-(hydroxyphenyl)sulfone with formaldehyde as dye bleeding prevention agent is reported in U.S. Pat. No. 5,707,949.
The use of nitrogen-containing polymers is known for use in laundry applications, particularly for soil-release properties. Published PCT application WO-A-98/23714 discloses water-soluble use of nitrogen-containing soil-release polymers in detergent products. Some of these polymers are formed from acrylamide monomers and are polymerized with co-monomers that are amines of alkylacrylates. A nitrogen-containing soil release polymer is described in WO-A-98/23714 and is formed from dicarboxylic add monomers and hydrophilic co-monomers that are secondary amines, which contain (poly)alkyleneoxy groups. Published PCT application WO-A-98/23714 discloses polymers formed from alkyleneacrylate monomers having a terminal quaternary ammonium group and co-monomers, which are (meth)acrylic add or esters or salts thereof. The only example is a polymer formed from a cationic monomer, namely methacrylamidopropyl trimethylammonium chloride (MAPTAC), and anionic monomer, namely acrylic acid (AA) and a neutral monomer, namely isobutylacrylate (IsoBuA).
U.S. Pat. No. 3,749,682 discloses copolymers of polyvinylpyrrolidone (PVP) and vinyl acetate for use as soil anti-redeposition agents.
Published PCT application WO-97/42285 discloses cotton soil-release polymers comprising a polyamine backbone and quaternary ammonium cationic groups.
Published European patent application 995,791 discloses a broad range of hydrophobically modified polycarboxylate polymers that are said to be useful for promoting soil release from fabrics, particularly cotton and cotton-containing fabrics. The polymers can comprise up to three moieties A, B and C wherein A is a polymerized residue of a monomer selected from one or more C3-C8 monoethylenically unsaturated carboxylic acids, B is a polymerized residue of a monomer selected from one or more C3-C60 alkyl (meth)acrylates, ethoxylated C1-C24 alkyl (meth)acrylates, and poly(alkylene glycol) (meth)acrylates, alkyl or aromatic ethers of poly(alkylene glycol) and the corresponding maleate mono and di-esters thereof, and C is a polymerized residue of a monomer selected from one or more ethylenically unsaturated monomers which are copolymerizable with the monomers in A and B.
According to published British patent application 2,104,091, copolymers of anionic and cationlc vinyl monomers can be used as detergency builders, for a wide range of detergent products, e.g. for ware washing, hard surface cleaning, textile cleaning and hair products.
U.S. Pat. No. 5,783,533 discloses various amphoteric copolymers as rheological modifiers of lamellar phases of detergent or cosmetic compositions.
JP-A-59135293 discloses detergent compositions, which contain an amphoteric copolymer consisting of at least 10 mol % cationic vinyl monomer units, at least 10 mol % anionic vinyl monomer units and at least 10 mol % nonionic vinyl monomer units. The preferred proportion of cationic vinyl monomer units to anionic vinyl monomer units is a molar ratio from 1:2 to 2:1.
U.S. Pat. No. 5,413,731 disposes water-soluble terpolymers, which are useful in automatic machine dishwashing detergent formulations. These terpolymers contain as polymerized units (a) from about 92 to about 30% by weight of one or more C3-C6 monoethylenically unsaturated carboxylic acids, (b) from about 5 to about 50% by weight of one or more aminoacryloyl derivatives, and (c) from about 25% by weight of one or more monoethylenically unsaturated monomers polymerizable with (a) and (b).